燃油组分对汽油机颗粒物及可挥发性有机物排放的影响

Impact of Fuel Components on PM and VOCs Emissions from Gasoline Engines

通过试验研究了燃油组分对进气道喷射(PFI)和缸内直喷(GDI)汽油机颗粒物及可挥发性有机物(VOCs)排放的影响.结果表明:燃油中的芳烃、烯烃和硫含量越高,颗粒排放也越高;通过添加少量甲基茂基三羰基锰能够保证不降低辛烷值的同时减少燃油芳香烃与烯烃含量从而使颗粒物排放降低;往燃油中添加10%,乙醇对颗粒物排放影响不大.PFI发动机排放的颗粒物成分主要由有机物(OM)组成,无机离子与元素碳(EC)含量较少.而GDI发动机排放的颗粒物主要以EC、OM为主,无机离子成分很少.燃油中芳烃含量越高,其颗粒物中多环芳烃(PAHs)的排放也越高,毒性也更强;燃油中烯烃含量的上升对颗粒物中PAHs的排放影响不大,但是其排放颗粒物中PAHs的毒性变强.检测到汽油机排放的VOCs由70余个物种组成,主要是烷烃、烯烃、芳烃、含氧挥发性有机物和炔烃.燃用高芳烃含量燃油,VOCs中芳烃比例有所上升.

Studies the impact of fuel components on particulate matter（PM）and volatile organic compounds（VOCs） emissions from a gasoline port fuel injection（PFI） engine and a gasoline direct injection（GDI）engine.Results show that,higher proportion of aromatics,alkenes or sulfur in gasoline fuel will lead to higher PM emissions.A small amount of methylcyclopentadienyl manganese tricarbonyl（MMT） can reduce the proportion of aromatics and alkenes gasoline fuel and thus reduce PM emissions. 10% of ethanol added to fuel has little effect on PM emissions.The PM from the PFI engine mainly consists of organic matter（OM） and a small amount of elemental carbon（EC） and inorganic ions,while the PM discharge from the GDI engine mainly consists of EC,OM and a small amount of inorganic ions.Higher proportion of aromatics in gasoline fuel will lead to higher polycyclic aromatic hydrocarbons（PAHs） emissions,and the toxicity of PAHs is stronger.Higher proportion of alkenes in gasoline fuel has little influence on PAHs emissions,but the toxicity of PAHs is stronger.The VOCs emitted from the engines mainly compose of 70,kinds of organic matter,including alkane,alkenes,aromatics,oxygenated volatile organic compounds,and alkynes.Burning of the fuel with higher aromatics content results in higher content of aromatics in VOCs.